Post-Ischemic Bowel Stricture: CT Features in Eight Cases

Cross-sectional imaging of mimics of inflammatory bowel disease: not everything is Crohn's disease or ulcerative colitis

Acute and chronic bowel pathologies can often be mistaken for manifestations of inflammatory bowel disease (IBD), and there are many entities with imaging and clinical features that overlap with IBD, making diagnosis difficult. We describe multiple inflammatory, infectious, neoplastic, and vascular entities with imaging and clinical features that may mimic IBD, and highlight differentiating features to assist in diagnosis.

Artificial intelligence-based tools with automated segmentation and measurement on CT images to assist accurate and fast diagnosis in acute pancreatitis

OBJECTIVES

To develop an artificial intelligence (AI) tool with automated pancreas segmentation and measurement of pancreatic morphological information on CT images to assist improved and faster diagnosis in acute pancreatitis.

METHODS

This study retrospectively contained 1124 patients suspected for AP and received non-contrast and enhanced abdominal CT examination between September 2013 and September 2022. Patients were divided into training (N = 688), validation (N = 145), testing dataset [N = 291; N = 104 for normal pancreas, N = 98 for AP, N = 89 for AP complicated with PDAC (AP&PDAC)]. A model based on convolutional neural network (MSAnet) was developed. The pancreas segmentation and measurement were performed via eight open-source models and MSAnet based tools, and the efficacy was evaluated using dice similarity coefficient (DSC) and intersection over union (IoU). The DSC and IoU for patients with different ages were also compared. The outline of tumour and oedema in the AP and were segmented by clustering. The diagnostic efficacy for radiologists with or without the assistance of MSAnet tool in AP and AP&PDAC was evaluated using receiver operation curve and confusion matrix.

RESULTS

Among all models, MSAnet based tool showed best performance on the training and validation dataset, and had high efficacy on testing dataset. The performance was age-affected. With assistance of the AI tool, the diagnosis time was significantly shortened by 26.8% and 32.7% for junior and senior radiologists, respectively. The area under curve (AUC) in diagnosis of AP was improved from 0.91 to 0.96 for junior radiologist and 0.98 to 0.99 for senior radiologist. In AP&PDAC diagnosis, AUC was increased from 0.85 to 0.92 for junior and 0.97 to 0.99 for senior.

CONCLUSION

MSAnet based tools showed good pancreas segmentation and measurement performance, which help radiologists improve diagnosis efficacy and workflow in both AP and AP with PDAC conditions.

ADVANCES IN KNOWLEDGE

This study developed an AI tool with automated pancreas segmentation and measurement and provided evidence for AI tool assistance in improving the workflow and accuracy of AP diagnosis.

Delayed bowel stenosis following subtotal resection of the small intestine for non-occlusive mesenteric ischemia

We report herein a case of delayed bowel stenosis after surgery for non-occlusive mesenteric ischemia (NOMI), which was successfully treated with endoscopic stenting. The patient was a 78-year-old woman who underwent an emergency laparotomy for NOMI and duodeno-ileal anastomosis. Necrosis was observed in almost all areas of the small intestine except for the beginning of the jejunum and the end of the ileum. Postoperatively, the patient was discharged with central venous nutrition, but was readmitted on postoperative day 54 with a diagnosis of postoperative ileus. The patient failed to respond to conservative treatment. Fluoroscopic endoscopy revealed wall stiffness and circumferential stenosis in the ascending colon at a different site from that of the anastomosis. Based on this finding, delayed stenosis of the ascending colon after NOMI treatment was diagnosed. Bougie dilatation was performed for the stenosis, leading to temporary improvement. However, stenosis along with ileus soon recurred. To prevent restenosis, a metallic stent was endoscopically implanted at the stenotic site. Thereafter, the patient was discharged without any further episodes of restenosis. Delayed bowel stenosis may occur after a subtotal resection of the small intestine for NOMI. Endoscopic stenting is an effective treatment option if resection is difficult.

Pearls and Pitfalls of Imaging Small Bowel Obstruction

Small bowel obstruction (SBO) is a common condition encountered by radiologists in the evaluation of patients with abdominal pain, and is an important diagnosis to be comfortable with given substantial associated morbidity and mortality. In this review, we summarize an imaging approach to evaluating patients with suspected SBO, discuss the role of certain imaging modalities such as radiography and small bowel follow through, CT, and MRI, as well as review some common and also less common causes of SBO such as internal hernia. We will also discuss tailoring the imaging approach to address specific clinical questions and special patient populations such as imaging the pregnant patient with suspected SBO, and the inflammatory bowel disease patient.

Jejunal stenosis as a sequela after laparoscopic sleeve gastrectomy for morbid obesity: a case series

Porto-mesenteric venous thrombosis (PMVT) is a rare complication that is encountered in less than 1% of patients following laparoscopic sleeve gastrectomy (LSG). This condition could be conservatively managed in stable patients with no evidence of peritonitis or bowel wall ischemia. Nonetheless, conservative management may be followed by ischemic small bowel stricture, which is poorly reported in the literature. Herein, we present our experience regarding three patients who presented with manifestations of jejunal stricture after initial successful conservative management of PMVT. Retrospective analysis of patients who developed jejunal stenosis as a sequela after LSG. The three included patients had undergone LSG with an uneventful post-operative course. All of them developed PMVT that was conservatively managed mainly by anticoagulation. After they were discharged, all of them returned with manifestations of upper bowel obstruction. Upper gastrointestinal series and abdominal computed tomography confirmed the diagnosis of jejunal stricture. The three patients were explored via laparoscopy, and resection anastomosis of the stenosed segment was performed. Bariatric surgeons should be aware of the association between PMVT, following LSG, and ischemic bowel strictures. That should help in the rapid diagnosis of the rare and difficult entity.

A Novel Chronic Enteropathy Associated with SLCO2A1 Gene Mutation: Enterography Findings in a Multicenter Korean Registry

OBJECTIVE

Chronic enteropathy associated with SLCO2A1 gene (CEAS) is a recently recognized disease. We aimed to evaluate the enterographic findings of CEAS.

MATERIALS AND METHODS

Altogether, 14 patients with CEAS were confirmed based on known SLCO2A1 mutations. They were registered in a multicenter Korean registry between July 2018 and July 2021. Nine of the patients (37.2 ± 13 years; all female) who underwent surgery-naïve-state computed tomography enterography (CTE) or magnetic resonance enterography (MRE) were identified. Two experienced radiologists reviewed 25 and 2 sets of CTE and MRE examinations, respectively, regarding the small bowel findings.

RESULTS

In initial evaluation, eight patients showed a total of 37 areas with mural abnormalities in the ileum on CTE, including 1-4 segments in six and > 10 segments in two patients. One patient showed unremarkable CTE. The involved segments were 10-85 mm (median, 20 mm) in length, 3-14 mm (median, 7 mm) in mural thickness, circumferential in 86.5% (32/37), and showed stratified enhancement in the enteric and portal phases in 91.9% (34/37) and 81.8% (9/11), respectively. Perienteric infiltration and prominent vasa recta were noted in 2.7% (1/37) and 13.5% (5/37), respectively. Bowel strictures were identified in six patients (66.7%), with a maximum upstream diameter of 31-48 mm. Two patients underwent surgery for strictures immediately after the initial enterography. Follow-up CTE and MRE in the remaining patients showed minimal-to-mild changes in the extent and thickness of the mural involvement for 17-138 months (median, 47.5 months) after initial enterography. Two patients required surgery for bowel stricture at 19 and 38 months of follow-up, respectively.

CONCLUSION

CEAS of the small bowel typically manifested on enterography in varying numbers and lengths of abnormal ileal segments that showed circumferential mural thickening with layered enhancement without perienteric abnormalities. The lesions caused bowel strictures that required surgery in some patients.

A Late Presentation of COVID-19 Induced Bowel Ischemia

Introduction

Infection with COVID-19 may lead to extrapulmonary pathologies secondary to the systemic inflammatory effects of the virus.

Case Description

This case report discusses a 55-year-old female patient who presented with small bowel obstruction (SBO) several months after resolution of a COVID-19 infection. The patient was surgically treated with a small bowel resection, and eventually made a full recovery.

Discussion

The pathophysiology of COVID-19-induced SBO can be explained by the prolonged inflammation and coagulation activation in the bowel's vasculature system. Under these circumstances, microthrombosis occurs in the bowel's microvasculature; the affected intestinal tissue becomes ischemic and infarcted. The damaged bowel is eventually replaced with fibrotic scar tissue, thus promoting bowel stricture and subsequent obstruction.

Conclusion

COVID-19 can be responsible for both acute and chronic embolic and thrombotic events in the mesenteric vasculature, which acts as a risk factor in the manifestation of SBO.

Protein-losing enteropathy caused by a jejunal ulcer after an internal hernia in Petersen's space: A case report

BACKGROUND

The incidence of internal hernias has recently increased in concordance with the popularization of laparoscopic surgery. Of particular concern are internal hernias occurring in Petersen's space, a space that is surgically created after treatment for gastric cancer and obesity. These hernias cause devastating sequelae, such as massive intestinal necrosis, fatal Roux limb necrosis, and superior mesenteric vein thrombus. In addition, protein-losing enteropathy (PLE) is a rare syndrome involving gastrointestinal protein loss, although its relationship with internal Petersen’s hernias remains unknown.

CASE SUMMARY

A 75-year-old man with a history of laparotomy for early gastric cancer developed Petersen's hernia 1 year and 5 mo after surgery. He was successfully treated by reducing the incarcerated small intestine and closure of Petersen’s defect without resection of the small intestine. Approximately 3 mo after his surgery for Petersen’s hernia, he developed bilateral leg edema and hypoalbuminemia. He was diagnosed with PLE with an alpha-1 antitrypsin clearance of 733 mL/24 h. Double-balloon enteroscopy revealed extensive jejunal ulceration as the etiology, and it facilitated minimum bowel resection. Pathological analysis showed extensive jejunal ulceration and collagen hyperplasia with nonspecific inflammation of all layers without lymphangiectasia, lymphoma, or vascular abnormalities. His postoperative course was unremarkable, and his bilateral leg edema and hypoalbuminemia improved after 1 mo. There was no relapse over the 5-year follow-up period.

CONCLUSION

PLE and extensive jejunal ulceration may occur after Petersen's hernia. Double-balloon enteroscopy helps identify and resect these lesions.

Smooth muscle degeneration of the mesenteric and branching veins causing ischemic enteritis: a case report

Background

Ischemic bowel injuries are generally caused by arteriosclerosis, thromboembolism, or vasculitis. Ischemic enteritis is less common than ischemic colitis because of the rich collateral arteries of the small intestine. In the present case, smooth muscle degeneration of the mesenteric to the submucosal veins caused ischemic enteritis and small bowel obstruction.

Case presentation

An 85-year-old woman with recurrent enteritis eventually developed small bowel obstruction. We performed laparoscopic partial resection of the small intestine. The pathological findings revealed smooth muscle degeneration of the mesenteric veins that caused ischemic enteritis. Venous changes were detected not only in the injured region, but also in a part of the normal region of the resected specimen. She continued to experience some minor symptoms postoperatively; however, these symptoms subsided in a short period with medicine discontinuation.

Conclusion

This report shows the possibility that a disease causes ischemic enteritis with unique venous pathological changes and may recur postoperatively.

Diagnosis of Fibrotic Distal Ileum Stenosis after Ischemic Enteritis Using Transabdominal Ultrasonography

Ischemic enteritis (IE) is a rare disorder which is caused by inadequate blood flow to small intestine. The diagnostic procedure of this disease has not sufficiently established because of its rarity. Here, we report a case of IE in a hemodialysis-dependent 70-year-old man and summarize the diagnostic options for IE. The patient was admitted to our hospital because of acute abdominal distention and vomiting. He presented with mild tenderness in the lower abdomen and slightly elevated C-reactive protein level as revealed by blood tests. Radiographic imaging showed small bowel obstruction due to a stricture in the distal ileum. Contrast-enhanced abdominal ultrasonography revealed a 7-cm stenotic site with increased intestinal wall thickening, which preserved mucosal blood perfusion. Elastography revealed a highly elastic alteration of the stenotic lesion, indicating benign fibrotic changes resulting from chronic insufficient blood flow. Based on a clinical diagnosis of IE with fibrous stenosis, a partial ileostomy was performed. After surgical treatment, oral intake was initiated without recurrence of intestinal obstruction. Pathological findings revealed deep ulceration with inflammatory cell infiltration at the stenotic site. Occlusion and hyalinization of the venules in the submucosal layer indicated IE. In addition to current case, we reviewed past case reports of IE. Through this case presentation and literature review, we summarize the usefulness and safety of transabdominal ultrasonography for diagnosing IE.

Management of post-traumatic ischaemic ileal stricture using intraoperative indocyanine green fluorescence-guided resection

Blunt abdominal trauma can affect mesenteric circulation which may lead to bowel strictures. Indocyanine green (ICG) angiography can be used to assess mesenteric blood flow and bowel perfusion as a guide to resect length intraoperatively. But this concept has not been applied to ischaemic bowel strictures. We present a case of ischaemic ileal stricture induced by blunt abdominal trauma which was managed by resection and anastomosis. Intraoperative near-infrared (NIR) ICG angiography was used as a guide to resect the bowel length. This case emphasises that ischaemic bowel strictures should be suspected in patients presenting with intestinal obstruction following trauma. Resection and anastomosis of the affected segment remains the primary treatment modality with excellent outcomes. NIR ICG angiography is a real-time objective and useful resource for assessing bowel perfusion and could be used to determine the length of the segment to be resected in patients with ischaemic bowel stricture.

Colonic Stricture Secondary to Recurrent Ischemic Colitis

Colonic ischemia is the most common form of gastrointestinal ischemia, which frequently affects the elderly population. The diagnosis and treatment can be challenging since it is prevalent in patients who are debilitated and have multiple comorbidities. However, most cases remain undetected until further complications emerge. Some of these patients will develop prolonged complications like chronic ischemic colitis or stricture requiring surgical intervention. Here we present a case of a colonic stricture secondary to recurrent ischemic colitis in an elderly female patient with multiple medical problems.

Usefulness of a finger-mounted tissue oximeter with near-infrared spectroscopy for evaluating the intestinal oxygenation and viability in rats

PURPOSE

To investigate the utility of the device for evaluating intestinal oxygenation and viability using an animal model.

METHODS

Sprague-Dawley rats underwent laparotomy under general anesthesia, and the blood vessels in the terminal ileum were clamped to create ischemia. We measured the regional tissue oxygenation saturation (rSO2) using an oximeter after 1, 3, and 6 h of vessel clamping. Ischemic tissue damage was assessed using a histological score. The intestine was reperfused after each clamping period, and intestinal rSO2 and survival rate were evaluated.

RESULTS

When reperfusion was performed at 1 and 3 h after ischemia, rSO2 increased after 10 min, and it improved to the same level as for normal intestine after 1 h; all rats survived for 1 week. In contrast, after 6 h of ischemia, rSO2 did not increase after reperfusion, and all animals died within 2 days. The histological scores increased after 1 h of reperfusion, with longer clamping periods.

CONCLUSION

A finger-mounted tissue oximeter could evaluate intestinal ischemia and the viability, which is thus considered to be a promising result for future clinical application.

Idiopathic mesenteric phlebosclerosis: clinical and CT imaging characteristics

Background

The aim of our study was to evaluate the clinical characteristics and computed tomography (CT) imaging findings of idiopathic mesenteric phlebosclerosis (IMP).

Methods

From January 2013 to May 2019, the clinical data of 10 patients diagnosed with IMP were analyzed retrospectively. Computed tomography angiography (CTA) and colonoscopy were performed in all 10 patients. All CT imaging findings were evaluated by three radiologists, including the form and distribution of calcification, the bowel's thickness, and the surrounding fat gap. The calcification score was calculated according to the extent of the involved mesenteric veins. The colonic wall thickness was defined as the average value of the thickest and thinnest regions of the intestinal wall. The correlation between the calcification scores and the colonic wall thickness was analyzed using Spearman's correlation analysis.

Results

All 10 patients were male with an average age of 59.6 years (range, 51-83 years). The average smoking index was 712 (range, 0-1,800). Among them, 7 patients had a history of long-term excessive daily intake of medicinal liquor or Chinese herbal medicine. Clinical symptoms of abdominal pain, diarrhea, bloating, and nausea were found. Colonoscopy showed dark purple discolorations of the edematous mucosa, engorged blood vessels, extensive erosion, ulceration, and multi-focal nodular surface in all patients. CT demonstrated colonic wall thickening, calcification along the mesenteric vein, and blurry surrounding fat gap in all 10 patients. Mesenteric venous calcification involved the terminal ileum, the ascending and transverse colon in all patients, and the descending colon and sigmoid colon's involvement in two patients. A total of 33 segments of the intestinal wall were involved. The median calcification score was 6 points, the mean thickness of the colonic wall was 10.73±3.22 mm, and there was no significant correlation (P=0.782) between calcification score and thickness of the colonic wall.

Conclusions

The main features of IMP are mesenteric venous calcification, colonic wall thickness, and pericolic fat stranding, and there is no correlation between calcification score and colonic wall thickness. Therefore, CT imaging combined with colonoscopy can improve the diagnostic accuracy of IMP.

Ischaemic colitis: practical challenges and evidence-based recommendations for management

Ischaemic colitis (IC) is a common condition with rising incidence, and in severe cases a high mortality rate. Its presentation, severity and disease behaviour can vary widely, and there exists significant heterogeneity in treatment strategies and resultant outcomes. In this article we explore practical challenges in the management of IC, and where available make evidence-based recommendations for its management based on a comprehensive review of available literature. An optimal approach to initial management requires early recognition of the diagnosis followed by prompt and appropriate investigation. Ideally, this should involve the input of both gastroenterology and surgery. CT with intravenous contrast is the imaging modality of choice. It can support clinical diagnosis, define the severity and distribution of ischaemia, and has prognostic value. In all but fulminant cases, this should be followed (within 48 hours) by lower gastrointestinal endoscopy to reach the distal-most extent of the disease, providing endoscopic (and histological) confirmation. The mainstay of medical management is conservative/supportive treatment, with bowel rest, fluid resuscitation and antibiotics. Specific laboratory, radiological and endoscopic features are recognised to correlate with more severe disease, higher rates of surgical intervention and ultimately worse outcomes. These factors should be carefully considered when deciding on the need for and timing of surgical intervention.

Noncontrast MRI of acute abdominal pain caused by gastrointestinal lesions: indications, protocol, and image interpretation

Gastrointestinal tract lesions are major causes of acute abdominal pain. A rapid, accurate, and reliable diagnosis is required to manage patients. Magnetic resonance imaging (MRI) is a nonionizing modality that is beneficial for pregnant women, children, and young adults who are sensitive to ionizing radiation. For patients with renal impairment who are not accurately diagnosed with noncontrast computed tomography, noncontrast MRI can serve as an alternative diagnostic modality. MRI protocols used for acute abdominal pain are supposed to be optimized and prioritized to shorten scanning times. Single-shot T2-weighted and fat-suppressed T2-weighted imaging are important pulse sequences that are used to reveal pathology and inflammation in the gastrointestinal tract. Diffusion-weighted imaging clearly depicts inflammation and abscesses as hyperintense lesions. Most acute gastrointestinal tract lesions, including inflammation, ischemia, obstruction, and perforation, demonstrate bowel wall thickening. Bowel obstruction and adynamic ileus present bowel dilatation, and perforation and penetration show bowel wall defects. MRI can be used to reveal these pathological findings with some characteristics depending on their underlying pathophysiology. This review article discusses imaging modalities for acute abdominal pain, describes a noncontrast MRI protocol for acute abdominal pain caused by gastrointestinal tract lesions, and reviews MRI findings of acute gastrointestinal tract lesions.

Ultrasonographic and histopathological features in 8 cats with fibrotic small intestinal stricture

Benign stricture is an uncommon cause of chronic small intestinal obstruction in the cat. The purpose of this retrospective case series was to describe the ultrasonographic features, histopathological findings, and clinical presentation in a group of cats with benign small intestinal stricture. Inclusion criteria were cats presenting during the period 2010-2017, and that had ultrasonography and small intestinal stricture confirmed at surgery. For each cat, clinical data and ultrasonographic findings were retrieved from the medical record, and histopathology, where available, was reviewed. Eight cats met the inclusion criteria. The location of strictures was duodenum (1/8), mid- to distal jejunum (4/8), and ileum (3/8). Ultrasonographic findings included gastric distension (8/8) and generalized (3/8) or segmental (5/8) intestinal dilation consistent with mechanical obstruction. Ingesta did not propagate beyond the strictured segment. Wall thickening was mild to moderate (3-6 mm). Normal wall layering was disrupted in all cats. Strictures were predominantly hypoechoic (7/8) and associated with hyperechoic peri-intestinal mesentery (6/8). Annular strictures (5/8) were less than 15 mm in length whereas long-segment strictures (3/8) were greater than 15 mm in length. Histopathology showed transmural disease with fibrosis and inflammation (8/8), often (6/8) extending into the bordering mesentery. The mucosa was the most severely affected layer and epithelial injury accompanied the mucosal fibrosis/inflammation. Clinical presentation reflected delayed diagnosis of chronic bowel obstruction with debilitation (8/8), marked weight loss (8/8), and prerenal azotemia (5/8). Benign fibrostenotic stricture should be considered a differential diagnosis in debilitated young cats presenting with chronic bowel disease and ultrasonographic features of intestinal obstruction.

Age of Data in Contemporary Research Articles Published in Representative General Radiology Journals

Objective

To analyze and compare the age of data in contemporary research articles published in representative general radiology journals.

Materials and Methods

We searched for articles reporting original research studies analyzing patient data that were published in the print issues of the Korean Journal of Radiology (KJR), European Radiology (ER), and Radiology in 2017. Eligible articles were reviewed to extract data collection period (time from first patient recruitment to last patient follow-up) and age of data (time between data collection end and publication). The journals were compared in terms of the proportion of articles reporting the data collection period to the level of calendar month and regarding the age of data.

Results

There were 50, 492, and 254 eligible articles in KJR, ER, and Radiology, respectively. Of these, 44 (88%; 95% confidence interval [CI]: 75.8-94.8%), 359 (73%; 95% CI: 68.9-76.7%), and 211 (83.1%; 95% CI: 78-87.2%) articles, respectively, provided enough details of data collection period, revealing a significant difference between ER and Radiology (p = 0.002). The age of data was significantly greater in KJR (median age: 826 days; range: 299-2843 days) than in ER (median age: 570 days; range: 56-4742 days; p < 0.001) and Radiology (median age: 618; range: 75-4271 days; p < 0.001).

Conclusion

Korean Journal of Radiology did not fall behind ER or Radiology in reporting of data collection period, but showed a significantly greater age of data than ER and Radiology, suggesting that KJR should take measures to improve the timeliness of its data.